Method of making incendiary bullets



June 11, 1946. p BURDETT 2,402,@13

METHOD OF MAKING INQENDIARY BULLETS Filed March 11, 1945 2 Sheets-Sheet l 1 N V EN TOR. phazgvzzaurdezz P. H. BURDETT 1 METHOD OF MAKING INCENDIARY BULLETS 2 Sheets-Sheet 2 FiledMaroh ll, 1943 INVENTOR. P/LL'Z a}? HBu rde Z BY 1% v. .7 ,-,d

GENT Patented June 11, 1946 FFICE METHOD OF MAKING INCENDIARY BULLETS Philip H. Burdett, Bridgeport, Conn., assignor to Remington Arms Company, Inc., Bridgeport, Cnn., a corporation of Delaware Application March 11, 1343, Serial No. 478,765

1 Claim.

- This invention relates, in general, to ammunition, and, in particular, to an improved method of manufacturing incendiary projectiles.

'Incendiary or explosive projectiles, say of .30 and .50 caliber, comprise, in general, a jacket of copper, gilding metal or some harder metal such as copper coated steel, a core which may be either hollow or solid adapted to partially fill the jacket so as to provide a space for an incendiary or explosive charge and a suitable heel closure. I

.Ihe incendiary or explosive charge is usually a granular 0r pulverant material and may, for convenience, be referred to as powder. The term powdenf as used 'in this specification, is to be understood as referring to a material sensitive to friction or percussion which is placed in a projectile and functions upon impact of the projectile with the target; and not to the propellant which is placed behind the projectile, usually in a cartridge case, and serves the purpose of propelling the projectile.

While bullets of this type, and, in particular, those having hollow steel cores, have met with considerable success, they are relatively expensive and do not lend themselves to a high rate of production. Moreover, it has been found that in many cases the incendiary charge in the hollow core does not ignite on impact, and, consequently, is substantially ineliective. Further, considerable trouble has been caused by the steel punches whichhave been used to compress the incendiary charge into the bullet. These punches are, of course, profiled according to specifications to enter substantially freely into the bullet jacket. Not infrequently, however, due to permissible variations in the size of a jacket, the compression punch has either let the charge past during compression so that it has been spilled out in a wasteful and hazardous manner, or the end of the punch has dug into and sometimes punctured the'converging walls of the jacket as the punch approached the lower limit of its stroke.

An object of the invention is to provide an improved method of assemblin the elements of a jacketed bullet. A further object is to provide an improved method of compacting a charge in the nose of an incendiary or explosive bullet. A still further object is to compact an incendiary or other active mixture in the nose of a jacketed bullet by exerting pressure on the core of the bullet suflicient to alter its shape in conformity with the contour of the bullet jacket. The invention likewise includes other improvements in the construction and manufacture of incendiary bullets as will hereinafter appear.

In the drawings:

Fig. 1 is a front diagrammatic view of a bullet assembly machine.

Fig. 2 is a view partly in section of the elements which comprise the bullet of this invention.

Fig. 3 is an elevation partly in section showing the bulletjacket supported in a die of the bullet assembly machine, the jacket having been loaded with an incendiary charge and a core at preceding stations.

Fig. 4 shows the next step wherein the charge and core are compressed by the bullet assembling punch.

Fig. 5 shows the final operation of the assembling machine wherein the heel closure is formed on the end of the bullet.

Fig. 6 shows a sectional elevation view of one form of the completely assembled incendiary bullet.

Fig. 7 shows a modification of the bullet of Fig. 6.

Fig. 8 shows a further modification of the I incendiary bullet shown in Fig. 6.

Fig. 9 is an enlarged fragmentary view of a portion of the bullet shown in Fig. 4.

, Referring to the drawings, Fig. l exemplifies one embodiment of a bullet assembling machine adapted to be used to assemble the bullet of the present invention and comprises a frame Ill having a vertically reciprocating gate ll adapted to carry a plurality of bullet assembling elements, indicated generally at 12, each end of the gate being slidably supported in guide members l3 secured to the frame Ill. Suitable means for reciprocating the gate is indicated at M. neath the gate is located a bolster I5 secured at its opposite ends to the frame Ill and provided with a plurality of bullet supporting dies l6, see Figs. 3, 4 and 5, opposite respective assembling elements l2 of the gate.

The precise details of the bullet assembling elements l2 are immaterial to the present invention, it being sufficient to state that the bullet jackets are delivered in the usual manner to the first die or operating station 20 from a suitable hopper by a feed tube 22. A punch '23 at the next station may inspect for the presence of the jacket in the die 86. A powder hopper 24 is mounted at the next station and is adapted to deliver a predetermined'charge into the jacket. An inspection of the charge may be made by a feeler 25 at the next succeeding station. Following the inspection of the charge, a suitable core or slug may be delivered into the jacket from a suitable hopper 26, the core being pressed down into the jacket at the next station by a suitable punch 21 as hereinafter described. The next succeeding punches 28 and 29 illustrate'suitable crimping and swaging means for forming the heel closure on the end of the bullet.

It is to be understood that these various stations and operations are merely exemplary and that other combinations and modifications thereof may be used. I

The preferred form of jacket and core for the .30 or .50 caliber incendiary or explosive bullet of this invention are illustrated in Fig. 2. The jacket 30 is formed of gliding metal, or it may be copper coated steel, and comprises a cylindrical heel and body portion, the latter tapering into an ogive which has a thin section at 32 adjacent the nose of the jacket. The core 33 is a substantially cylindrical slug of soft metal such as lead or a mixture of lead and antimony and only slightly less in diameter than the greatest inside diameter of the jacket. Each end of the slug is formed with a relatively flat dome 34 to facilitate entry of the slug into the jacket and avoid scratching the inner walls thereof.

Although'the specific materials and substances named above are the preferred materials for making the core and jacket, it Will be understood that these materials are not to be understood as limiting the method of assembling the elements of the bullet.

In carrying out the method, a jacket of the form described above is delivered into a suitable supporting die I6 at station 20 and then transferred from this die to subsequent dies or stations 35 and 31 respectively where a predetermined charge 40, such as an incendiary or explosive mixture, is delivered loosely' into the jacket followed by the core or slug 33 which is loaded on top of the charge. The assembled elements of the bullet are shown in Fig. 3.

At station number 38, illustrated in Fig. 4, the punch 21 moves down upon the end of the core or slug and exerts a relatively great compression force thereon. force is transmitted by the core to the loose incendiary charge, whereby the latter is ultimately compacted firmly in the nose of the jacket. With the decrease in volume of the charge, the core or core-punch 33 is forced downwardly into that portion of the jacket which, due to the tapered contour of its ogive, is of less inside diameter than the diameter of the slug. The walls of the jacket are, of course, supported by the die it and hence resist deformation by the pressure of the core-punch. As 'aresult, the

' relatively soft core 33 is deformed, see Fig. 9, so

that its shape and size and in particular its noseend 33' is automatically varied to fit the inside contour of the jacket, thus forming a powdertight seal during compression of the charge. The steel punch 21 does not, of course, contact the narrowing portion of the walls of the jacket, and, due to the deformation of soft metal core-punch 3-3, any gouging r puncturing of the jacket walls by the core is prevented. When the punch 21 reaches the bottom of its predetermined stroke, the core has been compressed into the final shape shown in Figs. 5. through 9, the charge 40 being firmly compacted by the core into the nose of the jacket.

Fig. illustrates the next step in the assembly of' the bullet and provides a heel closure for securing the core in the bullet jacket. This operation is carried out by moving a suitable crimping or swaging tool 28 down onto the upstanding edges 42 of the heel end of the jacket so as to turn these edges over and embed them into the end of the core. The bullet is then removed from its supporting die and one or more cannelures may be formed thereon to complete the bullet as shown in Fig. 6. The bullet shown and described has a substantially square heel with ballistic characteristics comparable to an armor piercing bullet of like caliber and hence may be interspersed and fired to advantage in'the same gun.

It will be understood, however, that bullets having slightly different proportions and weights may be assembled in a similar manner. For example a boat-:tail bullet, such as shown in Fig. 7, may be formed by using a jacket and core of the proper sizes, suitable swaging punches 28 and 29 at stations 39 and 40 being used for shaping the boat-tail.

It will be evident that the boat-tail or tapered heel construction produces a somewhat'lighter bullet than the bullet shown in Fig. 6. In fact, the boat-tail bullet is. from a ballistic stand! point, substantially like a tracer projectile of the same caliber.

As a further modification, a bullet may be assembled in the above described manner and have a substantially square end provided with a cavity 43 in the bottom thereof as shown in Fig. 8. This form of incendiary or explosive bullet, like the boat-tail bullet, is adapted to be fired with bursts of tracer projectiles.

A bullet or projectile made in accordance with the above described process possesses the impor tant advantage of being economical and fur hermore enables less hazardous assembling methods. By compressing the active mixture into the nose of the bullet jacket by means of a soft metal core which comprises in effect a contour fitting auto.-

matic size varying punch, the spilling of powder is wholly eliminated and any gouging or puncturing of the jacket walls is prevented. More? over, substantially cylindrical lead slug cores can be produced much more readily and cheaply than hollow steel cores. Finally, .by using a lead core, there can be no steel-to-steel contact of punch and core during the assembly of the bullet.

What is claimed is:

In the assembl of a percussion sensitive projectile comprising a jacket of a relatively hard metal formed with a hollow conical point merging with a hollow cylindrical section; the method comprising the steps of introducing into said jacket a charge of a bulk percussion sensitive material sufiicient when uncompacted to fill said conical point and a part of said cylindrical section; inserting in said jacket, and upon said charge a slug of metal of such softness as to be deformable under pressure contact with said jacket without scoring the jacket metal said slug havin a transverse section which substantially fills the cylindrical section of said jacket; and then applying pressure to said metal slug to move said slug forwardly into a portion of said jacket nose while deforming a part of said slug to the configuration of said portion and compacting said charge into the remaining portion of said jacket nose.

PHILIP H. BURDE'I'I. 

